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Biomedical subjects

D Shimm

Publications and source records attributed to D Shimm.

6 recordsLinked to original sources

Neoadjuvant therapy for advanced head and neck cancer with allopurinol-modulated high dose 5-fluorouracil and cisplatin. A phase I-II study.

The combination of cisplatin (100 mg/m2) and 5-fluorouracil (5-FU) by continuous infusion (1 g/m2/day for 5 days) has been reported to produce a high response rate as neoadjuvant therapy for advanced squamous cell head and neck cancer. We sought to improve the response rate by increasing the dose of 5-FU to 1.5 g/m2/day and 2.0 g/m2/day with allopurinol modulation to reduce toxicity. The overall response rate in the 30 patients who received three courses of chemotherapy was 100% with a 50% complete response (CR) rate. A 50% CR rate was observed in patients with T3 (six of 12) and N3 (four of eight) disease. Six patients (four with CR) did not complete subsequent treatment as planned. Seven of 11 (63.6%) chemotherapy complete responders and three of 12 (25%) partial responders (one lost to follow-up) who received all planned treatment are free of disease. The major toxicity encountered was stomatitis (severe in 32%) followed by leukopenia. The maximum tolerated dose of 5-FU in this combination with allopurinol protection was 1.5 g/m2/day. Cisplatin plus high dose 5-FU does not appear to be associated with a higher CR rate than that reported with conventional doses of 5-FU and is more toxic.

Adult

A method for consistent precision radiation therapy.

Using a meticulous setup procedure in which repeated portal films were taken before each treatment until satisfactory portal verifications were obtained, a high degree of precision in patient positioning was achieved. A fluctuation from treatment to treatment, over 11 treatments, of less than +/- 0.10 cm (S.D.) for anatomical points inside the treatment field was obtained. This, however, only applies to specific anatomical points selected for this positioning procedure and does not apply to all points within the portal. We have generalized this procedure and have suggested a means by which any target volume can be consistently positioned which may approach this degree of precision.

Chondrosarcoma

Hairy cell leukemia-associated familial lymphoproliferative disorder: immunologic abnormalities in unaffected family members.

Three generations of a family were affected by hematologic malignancies: the proband had hairy cell leukemia, his brother chronic lymphocytic leukemia, his nephew cutaneous and central nervous system lymphoma, and his father chronic granulocytic leukemia. There was no clinical evidence for immune deficiency in 17 unaffected family members. Most family members had normal serum immunoglobulins and peripheral B-cells, but some had decreased T cells. Lymphocyte responses to phytohemagglutinin and concanavalin A were markedly reduced, while pokeweed mitogen responses were essentially normal. Delayed hypersensitivity responses determined by response to a 23-antigen skin test panel were markedly diminished, as were viral antibody titers. The decreased immune function in these family members suggests a role for the immune system in the emergence of hairy cell leukemia and other lymphoid malignancies, though further follow-up will be needed to see if other family members develop malignancies.

Adolescent

The CDRH Helix: an in vivo evaluation.

The Helix is an electromagnetic heating device used to induce regional/systemic hyperthermia for cancer therapy. It is a resonant device operating at about 82 MHz with an aperture size of 60 cm x 40 cm (elliptical) x 40 cm long. The Helix deposits power in tissues (or phantoms) by producing a predominantly axial electric field within its radiating aperture. Five pig experiments were performed to provide in vivo verification of specific absorption rate (SAR) measurements and electric field measurements which were obtained earlier in tissue-equivalent phantom and 0.9% saline, respectively. In addition to verifying the power deposition patterns found in phantoms, the pig experiments provided valuable insight into the capabilities and limitations of electromagnetic regional heating. For example, a kidney with limited blood flow, simulating a necrotic tumor, heated very well-although the highest temperature was not always measured there. Also, fat heating may be a problem, since excessive temperatures in the fat were observed in approximately 20% of the heatings. This paper compares the in vivo temperature measurements in pigs with SARs and electric field measurements obtained in phantoms, and also provides a brief overview of results of the Helix in clinical situations.

Adipose Tissue

Temperature distributions during clinical scanned, focused ultrasound hyperthermia treatments.

In this study a scanned focused ultrasound (SFUS) system was used to heat 66 tumours at various anatomical locations in 52 patients. A total of 160 treatments were given. On average, temperatures were measured in 14 or 15 locations in the scanned volume. The time-averaged temperatures over the 30 min treatment period in the best treatment of each tumour were 44.0 +/- 2.4 degrees C (mean +/- SD) and 39.6 +/- 1.5 degrees C at the location of the highest and lowest sensor, respectively. On average, 39% of the sensors were above 42.5 degrees C. When only the cases that were judged to be good candidates for the hyperthermia device were analysed, 64% of the sensors reached a temperature over 42.5 degrees C with the highest temperature achieved being 45.9 +/- 2.3 degrees C and the lowest 40.7 +/- 1.4 degrees C. Although the system tested has many technical limitations (for example, fixed frequency, beam geometry and power during the scan cycle), the results demonstrate that therapeutic temperatures can be achieved in many tumours. Significantly better temperatures are expected when all of the theoretical potential of scanned focused ultrasound systems has been used.

Body Temperature